| 摘要 |
PURPOSE:To detect displacement with less electric power consumption by dividedly executing n-times of the action for evaluating the capacity ratio of a variable capacitor, the capacity of which varies with the displacement and a fixed capacitor, the capacity of which is constant as the ratio of time duration. CONSTITUTION:The variable capacitor CX, the electrostatic capacity of which varies with the displacement is first connected to an integrator 10 and the positive integral action is executed by 1/n the reference time. The output voltage of the integrator is thereby gradually increased. The counting of clock pulses from an oscillator 10 by a counter 23 of a displacement detecting circuit 16 is then started and the negative integral action is executed by connecting the fixed capacitor CR to the integrator 10. The counting of the counter 23 is stopped when a reference voltage Vref is attained on dropping of the output voltage of the integrator 10. The value of the counter 23 corresponds to the displacement of the variable capacitor CX and the detection is executed with the less electric power consumption if the above-mentioned action is executed repeatedly n-times.
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